| 摘要 |
PURPOSE:To make possible mass production of the titled prisms by a method wherein monomer as the material is injected into a mirror-finished V-groove of the lower mold body attached to a side member, a mirror-finished upper mold is attached thereto and the polymerized triangle pole base body is cut at a desired width. CONSTITUTION:Lower mold body 2 having a mirror-finished V-groove and side member 3, 4 of the lower mold are fixed firmly by screws 5, then monomer of low molecular weight with which hardening accelerator, catalyst, etc. are mixed is injected into the V-groove and upper mold 6 having a mirror-finished surface is inserted into the lower mold body 2 through fixing shaft 2' and clamped. Polymerization of monomer is accelerated and hardened in this state. When hardening is completed, the upper mold 6 and the lower mold side members 3, 4 are removed from the lower mold body 2. A base body comprising a plastic triangle pole having an extremely flat surface is obtained. A desired triangle prism 1 can be obtained when the triangle pole is cut at a desired width l in the direction of the length L of this triangle pole. |
